pennywhistle[pen′ē hwis′əl, -wis′-]
pennywhistle definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
any of various fipple flutes of metal, wood, or plastic with open holes for fingering
Origin: probably because originally inexpensive
pennywhistle definition by American Heritage Dictionary
also penny whistlenoun
An inexpensive fipple flute, usually having a plastic mouthpiece and a tin body.